Hybrid immunity from SARS-CoV-2 infection and vaccination in Canadian adults: cohort study.

Background: Few national-level studies have evaluated the impact of 'hybrid' immunity (vaccination coupled with recovery from infection) from the Omicron variants of SARS-CoV-2.Methods: From May 2020 to December 2022, we conducted serial assessments (each of ~4000-9000 adults) examining SARS-CoV-2 antibodies within a mostly representative Canadian cohort drawn from a national online polling platform. Adults, most of whom were vaccinated, reported viral test-confirmed infections and mailed self-collected dried blood spots to a central lab. Samples underwent highly sensitive and specific antibody assays to spike and nucleocapsid protein antigens, the latter triggered only by infection. We estimated cumulative SARS-CoV-2 incidence prior to the Omicron period and during the BA.1/1.1 and BA.2/5 waves. We assessed changes in antibody levels and in age-specific active immunity levels.Results: Spike levels were higher in infected than in uninfected adults, regardless of vaccination doses. Among adults vaccinated at least thrice and infected more than six months earlier, spike levels fell notably and continuously for the nine months post-vaccination. By contrast, among adults infected within six months, spike levels declined gradually. Declines were similar by sex, age group, and ethnicity. Recent vaccination attenuated declines in spike levels from older infections. In a convenience sample, spike antibody and cellular responses were correlated. Near the end of 2022, about 35% of adults above age 60 had their last vaccine dose more than six months ago, and about 25% remained uninfected. The cumulative incidence of SARS-CoV-2 infection rose from 13% (95% CI 11-14%) before omicron to 78% (76-80%) by December 2022, equating to 25 million infected adults cumulatively. However, the COVID-19 weekly death rate during the BA.2/5 waves was less than half of that during the BA.1/1.1 wave, implying a protective role for hybrid immunity.Conclusions: Strategies to maintain population-level hybrid immunity require up-to-date vaccination coverage, including among those recovering from infection. Population-based, self-collected dried blood spots are a practicable biological surveillance platform.Funding: Funding was provided by the COVID-19 Immunity Task Force, Canadian Institutes of Health Research, Pfizer Global Medical Grants, and St. Michael's Hospital Foundation. PJ and ACG are funded by the Canada Research Chairs Program.

PCR Test Positivity and Viral Loads during Three SARS-CoV-2 Viral Waves in Mumbai, India.

SARS-CoV-2 polymerase chain reaction (PCR) tests generally report only binary (positive or negative) outcomes. Quantitative PCR tests can provide epidemiological information on viral transmission patterns in populations. SARS-CoV-2 transmission patterns during India's SARS-CoV-2 viral waves remain largely undocumented. We analyzed 2.7 million real-time PCR testing records collected in Mumbai, a bellwether for other Indian cities. We used the inverse of cycle threshold (Ct) values to determine the community-level viral load. We quantified wave-specific differences by age, sex, and slum population density. Overall, PCR positivity was 3.4% during non-outbreak periods, rising to 23.2% and 42.8% during the original (June-November 2020) and Omicron waves (January 2022), respectively, but was a surprisingly low 9.9% during the Delta wave (March-June 2021; which had the largest increase in COVID deaths). The community-level median Ct values fell and rose ~7-14 days prior to PCR positivity rates. Viral loads were four-fold higher during the Delta and Omicron waves than during non-outbreak months. The Delta wave had high viral loads at older ages, in women, and in areas of higher slum density. During the Omicron wave, differences in viral load by sex and slum density had disappeared, but older adults continued to show a higher viral load. Mumbai's viral waves had markedly high viral loads representing an early signal of the pandemic trajectory. Ct values are practicable monitoring tools.

Emirates Heart Health Project (EHHP): A protocol for a stepped-wedge family-cluster randomized-controlled trial of a health-coach guided diet and exercise intervention to reduce weight and cardiovascular risk in overweight and obese UAE nationals.

INTRODUCTION: Cardiovascular disease (CVD) is the most common cause of death both globally and in the United Arab Emirates. Despite public health measures and health education, the rates of death from CVD remain stable. Barriers previously identified to lifestyle changes include cultural reasons, boredom, and lack of family support. The Emirates Heart Health Project (EHHP) seeks to support healthy lifestyle changes through a family-based intervention using a health coach and fitness tracker. METHODS AND ANALYSIS: The EHHP is a stepped-wedge cluster-randomized trial with each cluster comprised of members of an extended family. Eligible participants will be ≥ 18 years of age, with BMI ≥ 25, have Emirati citizenship and be able to give informed consent for study participation. The cluster will have 16 weekly teaching sessions in the participants' family home by a health coach who will review individual weight, diet and exercise (monitored by a wearable fitness tracker). The clusters will have pre-intervention assessments of their weight and CVD risk profile and enter the intervention in randomized order. Each cluster will have a post-intervention assessment of the same measures. The primary outcome is weight reduction from baseline. Secondary outcomes will include change in CVD risk factors such as systolic and diastolic blood pressure, hemoglobin A1c, total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides, waist circumference, and BMI. A mixed linear model will be used for analysis, where the parameters measured at the end of each 16-week episode will be the outcome values. These will be analyzed such that baseline values (measured just prior to the start of an episode) will be fixed covariables. Random effects are the family units. This trial has been registered with the NIH at clinicaltrials.gov (NCT04688684) and is being reported using the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and TIDieR (Template for intervention description and replication) framework. TRIAL REGISTRATION: Clinicaltrials.gov NCT04688684.

Assessing the impact of adopting a competency-based medical education framework and ACGME-I accreditation on educational outcomes in a family medicine residency program in Abu Dhabi Emirate, United Arab Emirates.

Background: Competency-Based Medical Education (CBME) is now mandated by many graduate and undergraduate accreditation standards. Evaluating CBME is essential for quantifying its impact, finding supporting evidence for the efforts invested in accreditation processes, and determining future steps. The Ambulatory Healthcare Services (AHS) family medicine residency program has been accredited by the Accreditation Council of Graduate Medical Education-International (ACGME-I) since 2013. This study aims to report the Abu Dhabi program's experience in implementing CBME and accreditation. Objectives: Compare the two residents' cohorts' performance pre-and post-ACGME-I accreditation.Study the bi-annually reported milestones as a graduating residents' performance prognostic tool. Methods: All residents in the program from 2008 to 2019 were included. They are called Cohort one-the intake from 2008 to 2012, before the ACGME accreditation, and Cohort two-the intake from 2013 to 2019, after the ACGME accreditation, with the milestones used. The mandatory annual in-training exam was used as an indication of the change in competency between the two cohorts. Among Cohort two ACGME-I, the biannual milestones data were studied to find the correlation between residents' early and graduating milestones. Results: A total of 112 residents were included: 36 in Cohort one and 76 in Cohort two. In Cohort one, before the ACGME accreditation, no significant associations were identified between residents' graduation in-training exam and their early performance indicators, while in Cohort two, there were significant correlations between almost all performance metrics. Early milestones are correlated with the graduation in-training exam score. Linear regression confirmed this relationship after controlling the residents' undergraduate Grade Point Average (GPA). Competency development continues to improve even after residents complete training at Post Graduate Year, PGY4, as residents' achievement in PGY5 continues to improve. Conclusion: Improved achievement of residents after the introduction of the ACGME-I accreditation is evident. Additionally, the correlation between the graduation in-training exam and graduation milestones, with earlier milestones, suggests a possible use of early milestones in predicting outcomes.

Duration of immune protection of SARS-CoV-2 natural infection against reinfection.

BACKGROUND: The future of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic hinges on virus evolution and duration of immune protection of natural infection against reinfection. We investigated the duration of protection afforded by natural infection, the effect of viral immune evasion on duration of protection and protection against severe reinfection, in Qatar, between 28 February 2020 and 5 June 2022. METHODS: Three national, matched, retrospective cohort studies were conducted to compare the incidence of SARS-CoV-2 infection and coronavirus disease 2019 (COVID-19) severity among unvaccinated persons with a documented SARS-CoV-2 primary infection, to incidence among those infection-naïve and unvaccinated. Associations were estimated using Cox proportional hazard regression models. RESULTS: Effectiveness of pre-Omicron primary infection against pre-Omicron reinfection was 85.5% [95% confidence interval (CI): 84.8-86.2%]. Effectiveness peaked at 90.5% (95% CI: 88.4-92.3%) in the 7th month after the primary infection, but waned to ~ 70% by the 16th month. Extrapolating this waning trend using a Gompertz curve suggested an effectiveness of 50% in the 22nd month and < 10% by the 32nd month. Effectiveness of pre-Omicron primary infection against Omicron reinfection was 38.1% (95% CI: 36.3-39.8%) and declined with time since primary infection. A Gompertz curve suggested an effectiveness of < 10% by the 15th month. Effectiveness of primary infection against severe, critical or fatal COVID-19 reinfection was 97.3% (95% CI: 94.9-98.6%), irrespective of the variant of primary infection or reinfection, and with no evidence for waning. Similar results were found in sub-group analyses for those ≥50 years of age. CONCLUSIONS: Protection of natural infection against reinfection wanes and may diminish within a few years. Viral immune evasion accelerates this waning. Protection against severe reinfection remains very strong, with no evidence for waning, irrespective of variant, for over 14 months after primary infection.

Ramadan fasting outcome among high-risk patients.

BACKGROUND: There is a growing literature on guidelines regarding Ramadan fasting for chronic kidney disease (CKD) patients. However, most studies only consider the impact of fasting on renal function. This study additionally aims to assess factors influencing Ramadan fasting in patients with CKD. METHOD: This is a prospective before and after cohort study. CKD patients were counseled regarding fasting and followed-up post-Ramadan for renal function status, actual fasting behavior, and other relevant outcomes. RESULTS: Of the 360 patients who attended the pre-Ramadan consultation, 306 were reachable after Ramadan of whom 55.3% were female. Of these 306 67.1% reported that they had fasted, 4.9% had attempted to fast but stopped, and 28% did not fast at all. Of these 74 has a post-fasting kidney test. Of the patients, 68.1% had stage 3A CKD, 21.7% had stage 3B, 7.9% stage 4, and only 2% stage 5. Of those who fasted, 11.1% had a drop in Glomerular Filtration Rate (eGFR) of 20% or more. Those who did not fast (16.7%) presented a similar drop. Conversely, among the few who attempted to fast and had to stop, half showed a drop in eGFR of more than 20%. In linear regression, fasting was not associated with post-Ramadan eGFR, when controlling for age and baseline eGRF. There were 17 (5.6%) significant events, including one death. More significant events occurred among the group who fasted some of Ramadan days, 26.7% of the subjects experienced an adverse event-while 4.7% of the group who did not fast had a significant adverse event compared to 4.4% among those who fasted all Ramadan. CONCLUSION: Fasting was not a significant determining factor in renal function deterioration in the study's population, nor did it have any significant association with adverse events.

Sustained effect of LACTIN-V (Lactobacillus crispatus CTV-05) on genital immunology following standard bacterial vaginosis treatment: results from a randomised, placebo-controlled trial.

BACKGROUND: Bacterial vaginosis might increase HIV risk by eliciting genital inflammation and epithelial barrier disruption, whereas vaginal Lactobacillus crispatus is associated with immune quiescence and HIV protection. We investigated the effect of a live biotherapeutic containing L crispatus CTV-05 (LACTIN-V) on genital immunology and key vaginal bacteria. METHODS: This substudy included women aged 18-45 years who participated in the randomised, placebo-controlled, phase 2b trial of LACTIN-V to reduce bacterial vaginosis recurrence, conducted at four universities and hospitals in the USA. Women with negative results for sexually transmitted infection, pregnancy, and urinary tract infection were provided a 5-day course of vaginal metronidazole 0·75% gel. Those who met at least three of four clinical Amsel criteria for bacterial vaginosis and had a Nugent score of 4-10 from Gram staining were eligible. Participants in the LACTIN-V trial were randomly assigned (2:1) to receive either LACTIN-V or placebo, applied vaginally once per day for 5 days during the first week and then twice per week for 10 more weeks. Follow-up visits occurred 4, 8, 12, and 24 weeks after enrolment. Soluble immune factors and the absolute abundance of bacterial taxa were assayed by mutliplex ELISA and quantitative PCR. The primary outcomes were vaginal levels of IL-1α and soluble E-cadherin at 24 weeks (ie, 13 weeks after treatment cessation). FINDINGS: Between Feb 21, 2020 and March 18, 2021, we characterised genital immune parameters and the vaginal microbiota in a subset of 66 highly adherent participants who were randomly selected, with no exclusion criteria, from those who had attended all study follow-up visits (n=166) in the larger LACTIN-V clinical trial (n=288). 32 (48%) participants received LACTIN-V and 34 (52%) received placebo. LACTIN-V treatment was significantly associated with lower concentrations of the proinflammatory cytokine IL-1α (ß coefficient 0·310, SE 0·149; p=0·042) and soluble E-cadherin (0·429, 0·199; p=0·035), a biomarker of epithelial barrier disruption. INTERPRETATION: Vaginal administration of LACTIN-V following standard bacterial vaginosis therapy resulted in a sustained reduction in genital inflammation and a biomarker of epithelial integrity. The potential of LACTIN-V to reduce HIV susceptibility merits further investigation. FUNDING: Canadian Institutes of Health Research and the National Institutes of Health National Institute of Allergy and Infectious Diseases.

Metronidazole treatment rapidly reduces genital inflammation through effects on bacterial vaginosis-associated bacteria rather than lactobacilli.

BackgroundBacterial vaginosis (BV) causes genital inflammation and increases HIV risk, whereas a vaginal microbiota dominated by Lactobacillus species is associated with immune quiescence and relative HIV protection. BV treatment reduces genital inflammation, but it is unclear whether this reduction is driven by a decrease in BV-associated bacteria or an increase in Lactobacillus species.METHODSTo evaluate the short-term effect of standard BV treatment on genital immunology and the vaginal microbiota, vaginal swabs were collected immediately before and after metronidazole treatment for BV and analyzed with multiplex ELISA, metagenomic sequencing, and quantitative PCR.RESULTSTopical metronidazole treatment rapidly reduced vaginal levels of proinflammatory cytokines, chemokines, and soluble immune markers of epithelial barrier disruption. Although the vaginal microbiota shifted to dominance by L. iners or L. jensenii, this proportional shift was primarily driven by a 2 to 4 log10-fold reduction in BV-associated bacteria absolute abundance. BV treatment induced no change in the absolute abundance of L. crispatus or L. iners and only minor (<1 log10-fold) increases in L. gasseri and L. jensenii that were not independently associated with reduced inflammation in multivariable models.CONCLUSIONThe genital immune benefits that are associated with Lactobacillus dominance after BV treatment were not directly attributable to an absolute increase in lactobacilli, but rather to the loss of BV-associated bacteria.Trial REGISTRATIONParticipants were recruited as part of a randomized controlled trial (ClinicalTrials.gov NCT02766023) from 2016 to 2019.FUNDINGCanadian Institutes of Health Research (PJT-156123) and the National Institute of Allergy and Infectious Diseases (HHSN2722013000141 and HHSN27200007).

Risk factors for vitamin D deficiency in Abu Dhabi Emirati population.

OBJECTIVE: There have been concerns regarding the high prevalence of vitamin D deficiency in the United Arab Emirates and the association between this prevalence and cardiovascular risk. Vitamin D deficiency is a global public health problem, with a high prevalence in the Abu Dhabi national population. This cross-sectional retrospective observational study aimed to elucidate vitamin D deficiency symptoms and contributing factors in this context. METHOD AND SAMPLING: Among 12346 participants presenting for their Weqaya population comprehensive cardiovascular risk factor screening, 700 were randomly selected and telephoned, among whom 400 completed a questionnaire that elicited information on dietary intake, sun exposure, clothing, physical activity, and symptoms related to vitamin D deficiency. RESULTS: Higher vitamin D levels were noted in participants who consumed extra servings of cod liver oil, tuna, salmon, and eggs; who wore clothes with their arms and legs exposed; and who performed daily physical activity. Symptoms of hypovitaminosis D (bone pain) were more frequently found in females. Fatigue is significantly associated with low vitamin D and younger participants. Strategies focusing on health promotion and lifestyle interventions should be implemented to address vitamin D deficiency.

Assessment of SARS-CoV-2 Seropositivity During the First and Second Viral Waves in 2020 and 2021 Among Canadian Adults.

Importance: The incidence of infection during SARS-CoV-2 viral waves, the factors associated with infection, and the durability of antibody responses to infection among Canadian adults remain undocumented. Objective: To assess the cumulative incidence of SARS-CoV-2 infection during the first 2 viral waves in Canada by measuring seropositivity among adults. Design, Setting, and Participants: The Action to Beat Coronavirus study conducted 2 rounds of an online survey about COVID-19 experience and analyzed immunoglobulin G levels based on participant-collected dried blood spots (DBS) to assess the cumulative incidence of SARS-CoV-2 infection during the first and second viral waves in Canada. A sample of 19 994 Canadian adults (aged ≥18 years) was recruited from established members of the Angus Reid Forum, a public polling organization. The study comprised 2 phases (phase 1 from May 1 to September 30, 2020, and phase 2 from December 1, 2020, to March 31, 2021) that generally corresponded to the first (April 1 to July 31, 2020) and second (October 1, 2020, to March 1, 2021) viral waves. Main Outcomes and Measures: SARS-CoV-2 immunoglobulin G seropositivity (using a chemiluminescence assay) by major geographic and demographic variables and correlation with COVID-19 symptom reporting. Results: Among 19 994 adults who completed the online questionnaire in phase 1, the mean (SD) age was 50.9 (15.4) years, and 10 522 participants (51.9%) were female; 2948 participants (14.5%) had self-identified racial and ethnic minority group status, and 1578 participants (8.2%) were self-identified Indigenous Canadians. Among participants in phase 1, 8967 had DBS testing. In phase 2, 14 621 adults completed online questionnaires, and 7102 of those had DBS testing. Of 19 994 adults who completed the online survey in phase 1, fewer had an educational level of some college or less (4747 individuals [33.1%]) compared with the general population in Canada (45.0%). Survey respondents were otherwise representative of the general population, including in prevalence of known risk factors associated with SARS-CoV-2 infection. The cumulative incidence of SARS-CoV-2 infection among unvaccinated adults increased from 1.9% in phase 1 to 6.5% in phase 2. The seropositivity pattern was demographically and geographically heterogeneous during phase 1 but more homogeneous by phase 2 (with a cumulative incidence ranging from 6.4% to 7.0% in most regions). The exception was the Atlantic region, in which cumulative incidence reached only 3.3% (odds ratio [OR] vs Ontario, 0.46; 95% CI, 0.21-1.02). A total of 47 of 188 adults (25.3%) reporting COVID-19 symptoms during phase 2 were seropositive, and the OR of seropositivity for COVID-19 symptoms was 6.15 (95% CI, 2.02-18.69). In phase 2, 94 of 444 seropositive adults (22.2%) reported having no symptoms. Of 134 seropositive adults in phase 1 who were retested in phase 2, 111 individuals (81.8%) remained seropositive. Participants who had a history of diabetes (OR, 0.58; 95% CI, 0.38-0.90) had lower odds of having detectable antibodies in phase 2. Conclusions and Relevance: The Action to Beat Coronavirus study found that the incidence of SARS-CoV-2 infection in Canada was modest until March 2021, and this incidence was lower than the levels of population immunity required to substantially reduce transmission of the virus. Ongoing vaccination efforts remain central to reducing viral transmission and mortality. Assessment of future infection-induced and vaccine-induced immunity is practicable through the use of serial online surveys and participant-collected DBS.

Risk Factors for SARS-CoV-2 Infection Severity in Abu Dhabi.

BACKGROUND: Prediction models are essential for informing screening, assessing prognosis, and examining options for treatment. This study aimed to assess the risk of SARS-CoV-2 infection severity in the Abu Dhabi population. METHODS: This is a mixed retrospective cohort study and case-control study to explore the associated factors of receiving treatment in the community, being hospitalized, or requiring complex hospital care among patients with a diagnosis of SARS-CoV-2. Of 641 patients included, 266 were hospitalized; 135 were hospitalized and either died or required complex care, i.e., required ICU admission, intubation, or oxygen and 131 did not develop severe disease requiring complex care. The third group ("controls") were 375 patients who were not hospitalized. Logistic regression analyses were used to study predictors of disease severity. RESULTS: Among hospitalized patients older age and low oxygen saturation at admission were the consistent and strongest predictors of an adverse outcome. Risk factors for the death in addition to age and low oxygen saturation were elevated white blood count and low reported physical activity. Chronic kidney disease and diabetes were also associated with more severe disease in logistic regression. The mortality rate among those with less than 30 min per week of physical activity was 4.9%, while the mortality rate was 0.35% for those with physical activity > 30 min at least once a week. The interval from the onset of symptoms to admission and mortality was found to have a significant inverse relationship, with worse survival for shorter intervals. CONCLUSION: Oxygen saturation is an important measure that should be introduced at screening sites and used in the risk assessment of patients with SARS-CoV-2. In addition, an older age was a consistent factor in all adverse outcomes, and other factors, such as low physical activity, elevated WBC, CKD, and DM, were also identified as risk factors.

COVID-19 vaccination intention during early vaccine rollout in Canada: a nationwide online survey.

BACKGROUND: Understanding vaccination intention during early vaccination rollout in Canada can help the government's efforts in vaccination education and outreach. METHOD: Panel members age 18 and over from the nationally representative Angus Reid Forum were invited to complete an online survey about their experience with COVID-19, including their intention to get vaccinated. Respondents were asked "When a vaccine against the coronavirus becomes available to you, will you get vaccinated or not?" Having no intention to vaccinate was defined as choosing "No - I will not get a coronavirus vaccination" as a response. Odds ratios and predicted probabilities are reported for no vaccine intentionality in demographic groups. FINDINGS: 14,621 panel members completed the survey. Having no intention to vaccinate against COVID-19 is relatively low overall (9%) with substantial variation among demographic groups. Being a resident of Alberta (predicted probability = 15%; OR 0.58 [95%CI 0.14-2.24]), aged 40-59 (predicted probability = 12%; OR 0.87 [0.78-0.97]), identifying as a visible minority (predicted probability = 15%; OR 0.56 [0.37-0.84]), having some college level education or lower (predicted probability = 14%) and living in households of at least five members (predicted probability = 13%; OR 0.82 [0.76-0.88]) are related to lower vaccination intention. INTERPRETATION: The study identifies population groups with greater and lesser intention to vaccinate in Canada. As the Canadian COVID-19 vaccination effort continues, policymakers may use this information to focus outreach, education, and other efforts on the latter groups, which also have had higher risks for contracting and dying from COVID-19. FUNDING: Pfizer Global Medical, Unity Health Foundation, Canadian COVID-19 Immunity Task Force.

Impact of Ethnicity and Underlying Comorbidity on COVID-19 Inhospital Mortality: An Observational Study in Abu Dhabi, UAE.

BACKGROUND: The UAE reported its first cluster of COVID 2019 in a group of returned travellers from Wuhan in January 2020. Various comorbidities are associated with worse disease prognosis. Understanding the impact of ethnicity on the disease outcome is an important public health issue but data from our region is lacking. AIM: We aim to identify comorbidities among patients hospitalized for COVID-19 that are associated with inhospital death. Also, to assess if ethnicity is correlated with increased risk of death. Patients and Method. The study is a single-centre, observational study in Shaikh Shakhbout Medical City, Abu Dhabi. Patients admitted with COVID-19, between 1st of March and the end of May, were enrolled. Records were studied for demography, comorbidity, and ethnicity. Ethnicity was divided into Arabs (Gulf, North Africa, and the Levant), South Asia (India, Pakistan, Bangladesh, Nepal, and Afghanistan), Africans, the Philippines, and others. The study was approved by the Department of Health of Abu Dhabi. RESULTS: 1075 patients (972 males) were enrolled. There were 24 nationalities under 5 ethnicity groups. Mean (average) age was 51 years (20-81). 101 (9.4%) died with deceased patients being significantly older. Death risk was not significantly influenced by sex. Duration of hospitalization among survivors was 6.2 days (0.2-40.4) with older patients and men staying longer (P < 0.01). Comorbidities of diabetes, hypertension, cardiovascular disease, chronic renal disease, liver disease, and malignancy were associated with higher risk of mortality univariate, but only liver disease reached statistical significance after adjustment for age. The highest percentage of death was seen in Arab Levant (21.2) followed by the Asian Afghan (18.8); however, differences among ethnicities did not reach statistical significance (P = 0.086). CONCLUSION: COVID-19 outcome was worse in older people and those with comorbidities. Men and older patients required longer hospitalization. Ethnicity is not seen to impact the risk of mortality.

Predictors of self-reported symptoms and testing for COVID-19 in Canada using a nationally representative survey.

Random population-based surveys to estimate prevalence of SARS-CoV2 infection causing coronavirus disease (COVID-19) are useful to understand distributions and predictors of the infection. In April 2020, the first-ever nationally representative survey in Canada polled 4,240 adults age 18 years and older about self-reported COVID experience in March, early in the epidemic. We examined the levels and predictors of COVID symptoms, defined as fever plus difficulty breathing/shortness of breath, dry cough so severe that it disrupts sleep, and/or loss of sense of smell; and testing for SARS-CoV-2 by respondents and/or household members. About 8% of Canadians reported that they and/or one or more household members experienced COVID symptoms. Symptoms were more common in younger than in older adults, and among visible minorities. Overall, only 3% of respondents and/or household members reported testing for SARS-CoV-2. Being tested was associated with having COVID symptoms, Indigenous identity, and living in Quebec. Periodic nationally representative surveys of symptoms, as well as SARS-CoV-2 antibodies, are required in many countries to understand the pandemic and prepare for the future.

Clinical Presentation, Treatment, and Outcome of Acromegaly in the United Arab Emirates.

OBJECTIVES: We sought to ascertain the clinical characteristics and control rate of acromegaly in the UAE. METHODS: We conducted a multicenter retrospective analysis of all patients presenting with acromegaly to six endocrine centers in the UAE between November 2010 and December 2018. Demographic, clinical, biochemical, and radiologic data were collected. Patients were considered controlled if normal insulin-like growth factor-1 (IGF-1) level and growth hormone < 1 mcg/L were achieved at their last visit. RESULTS: A total of 75 patients were included in the study (60.0% males, 33.3% native UAE nationals). The mean age at diagnosis was 37.2 (range: 12-69) years. Common clinical features at diagnosis were headache (82.4%), coarse facial features (82.4%), acral enlargement (79.7%), and sweating (31.3%). Diabetes mellitus/prediabetes and hypertension were present in 45.2% and 35.5% of patients, respectively. About 82.2% had pituitary macroadenoma on pituitary magnetic resonance imaging. At presentation, 27.0% and 3.2% of the patients had secondary hypogonadism and diabetes insipidus, respectively. Overall, 76.7% of the patients underwent surgery, 20.8% received radiotherapy, and 50.7% received medical therapy. At their last clinic visit, only 43.7% of all patients achieved disease control. CONCLUSIONS: Our study shows a high prevalence of pituitary macroadenoma in our acromegalic population, suggesting a delayed diagnosis. Also, a significant proportion of patients remained uncontrolled. Efforts to increase physician's awareness of acromegaly and to improve disease control are underway.

Mapping and characterising areas with high levels of HIV transmission in sub-Saharan Africa: A geospatial analysis of national survey data.

BACKGROUND: In the generalised epidemics of sub-Saharan Africa (SSA), human immunodeficiency virus (HIV) prevalence shows patterns of clustered micro-epidemics. We mapped and characterised these high-prevalence areas for young adults (15-29 years of age), as a proxy for areas with high levels of transmission, for 7 countries in Eastern and Southern Africa: Kenya, Malawi, Mozambique, Tanzania, Uganda, Zambia, and Zimbabwe. METHODS AND FINDINGS: We used geolocated survey data from the most recent United States Agency for International Development (USAID) demographic and health surveys (DHSs) and AIDS indicator surveys (AISs) (collected between 2008-2009 and 2015-2016), which included about 113,000 adults-of which there were about 53,000 young adults (27,000 women, 28,000 men)-from over 3,500 sample locations. First, ordinary kriging was applied to predict HIV prevalence at unmeasured locations. Second, we explored to what extent behavioural, socioeconomic, and environmental factors explain HIV prevalence at the individual- and sample-location level, by developing a series of multilevel multivariable logistic regression models and geospatially visualising unexplained model heterogeneity. National-level HIV prevalence for young adults ranged from 2.2% in Tanzania to 7.7% in Mozambique. However, at the subnational level, we found areas with prevalence among young adults as high as 11% or 15% alternating with areas with prevalence between 0% and 2%, suggesting the existence of areas with high levels of transmission Overall, 15.6% of heterogeneity could be explained by an interplay of known behavioural, socioeconomic, and environmental factors. Maps of the interpolated random effect estimates show that environmental variables, representing indicators of economic activity, were most powerful in explaining high-prevalence areas. Main study limitations were the inability to infer causality due to the cross-sectional nature of the surveys and the likely under-sampling of key populations in the surveys. CONCLUSIONS: We found that, among young adults, micro-epidemics of relatively high HIV prevalence alternate with areas of very low prevalence, clearly illustrating the existence of areas with high levels of transmission. These areas are partially characterised by high economic activity, relatively high socioeconomic status, and risky sexual behaviour. Localised HIV prevention interventions specifically tailored to the populations at risk will be essential to curb transmission. More fine-scale geospatial mapping of key populations,-such as sex workers and migrant populations-could help us further understand the drivers of these areas with high levels of transmission and help us determine how they fuel the generalised epidemics in SSA.

Prevalence of vitamin D deficiency and associated comorbidities among Abu Dhabi Emirates population.

OBJECTIVE: The study explored the prevalence of vitamin D deficiency, its seasonal variation and associated comorbidities among the Abu Dhabi Emirati population living in urban and suburban settings. RESULT: Of the 12,346 participants 36.9% were male and 63.1% female. The majority (72%) were either vitamin D deficient (< 50 nmol/L), or (10%) vitamin D insufficient (50-74 nmol/L). Vitamin D deficiency was similar in both sexes (male 83.1% vs female 83.8%) as insufficiency (male 12.7% vs female 11.2%). Low vitamin D levels were associated with high blood pressure, high body mass index, central obesity, high cholesterol, impaired blood glucose levels and a high Framingham risk score. The mean vitamin D level was highest in January (winter) and lowest in July (summer).

Effects of tDCS of Dorsolateral Prefrontal Cortex on Dual-Task Performance Involving Manual Dexterity and Cognitive Task in Healthy Older Adults.

Healthy aging limits the activities of daily living and personal independence. Furthermore, cognitive-motor interference in dual-task (e.g., walking while talking) appears to be more pronounced in the elderly. Transcranial direct current stimulation (tDCS), a form of the non-invasive brain stimulation technique, is known to modify cortical excitability and has been investigated as a tool for enhancing motor and cognitive performance in health and disease. The present study examined whether tDCS targeting the dorsolateral prefrontal cortex (DLPFC) could improve dual-task performance in healthy older adults. The effects of tDCS, among other factors, depend on stimulation polarity (anodal vs. cathodal), electrode setup (unilateral vs. bilateral) and the time of application (off-line vs. on-line). We therefore explored the effects of unilateral and simultaneous bilateral tDCS (anodal and cathodal) of left DLPFC while performing (on-line) the Grooved Pegboard Test (GPT) and Serial Seven Subtraction Test (SSST) alone or together (dual-tasking). The number of pegs and the number of correct subtractions were recorded before, during and 30 min after tDCS. The dual-task performance was measured as the percent change from single- to the dual-task condition (dual-task cost DTC). Only bilateral, anode left tDCS, induced a significant increase in subtracted numbers while dual-tasking, i.e., it reduced the DTC of manual dexterity (GPT) to a cognitive task. Significant changes 30 min after the stimulation were only present after bilateral anode right (BAR) tDCS on GPT dual-task costs. These findings suggest that anodal tDCS applied on-line interacts with a dual-task performance involving demanding cognitive and manual dexterity tasks. The results support the potential use of non-invasive brain stimulation for improvement of cognitive functioning in daily activities in older individuals.